deleting data in text file

well, i have a homepage whereby users can key in data and that data will automatically be in my text file. i use pipe and the sample of the text file is like this:

aa|bb|cc|dd
ee|ff|ggg|fdg
rr|fdg|tfh|fcbv

from the web, user has to enter for fields, and that data will be inserted in the text file as above. it's working as what i wanted.
the problem is when i want to delete let's say the second row, how could i do it? can i do so? should i replace that row to blank? is there any delete command in perl??
answer with coding is really appreciated.
bye

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